<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <link rel="stylesheet" href="./css优化版/float_grid.css">
  <style>
    * {
      box-sizing: border-box;
      padding: 0;
    }
    .form-group {
      margin-bottom: 20px;
    }
    .form-group label {
      line-height: 30px;
    }
    .form-control {
      font-family: inherit;
      padding: 3px 8px;
      width: 100%;
    }
    .btn {
      font-family: inherit;
      padding: 3px 8px;
      cursor: pointer;
    }
  </style>
</head>

<body>
  <h1>栅格表单</h1>
  <form class="container">
    <div class="row">
      <div class="col-sm-6 col-md-4 col-lg-3">
        <div class="form-group">
          <label for="">账号</label>
          <input type="text"  class="form-control">
        </div>
      </div>
      <div class="col-sm-6 col-md-4 col-lg-3">
        <div class="form-group">
          <label for="">密码</label>
          <input type="password"  class="form-control">
        </div>
      </div>
      <div class="col-sm-6 col-md-4 col-lg-3">
        <div class="form-group">
          <label for="">账号</label>
          <input type="text"  class="form-control">
        </div>
      </div>
      <div class="col-sm-6 col-md-4 col-lg-3">
        <div class="form-group">
          <label for="">密码</label>
          <input type="password"  class="form-control">
        </div>
      </div>
      <div class="col-sm-6 col-md-4 col-lg-3">
        <div class="form-group">
          <label for="">账号</label>
          <input type="text"  class="form-control">
        </div>
      </div>
      <div class="col-sm-6 col-md-4 col-lg-3">
        <div class="form-group">
          <label for="">密码</label>
          <input type="password"  class="form-control">
        </div>
      </div>
      <div class="col-sm-6 col-md-4 col-lg-3">
        <div class="form-group">
          <label for="">账号</label>
          <input type="text" class="form-control">
        </div>
      </div>
      <div class="col-sm-6 col-md-4 col-lg-3">
        <div class="form-group">
          <label for="">密码</label>
          <input type="password"  class="form-control">
        </div>
      </div>
    </div> 
    <div class="form-group">
      <button class="btn">登录</button>
    </div>
  </form> 
 
</body>

</html>